Résumé de rapport

Solid adhesives for bonding the sole to the upper in the footwear industry

The bonding processes of upper to sole in footwear and of materials for leather goods are carried out mostly using solvent based adhesives which are potentially harmful both to the environment and to the operators that handle them. The alternative proposal that has been developed which consists of the use of solid adhesives in film form which supply a clean and quick technology for bonding and can markedly increase production.

The solid adhesives optimized present the following technical characteristics: products of a thermoplastic nature presented in film form; they are only applied to one of the surfaces to be joined; they are heat activated at temperatures that are in easy reach of conventional reactivation methods; the two surfaces are joined and pressed.

The joins produced with these products fulfil all the requirements needed for quality bonding in footwear and leather-goods, furthermore, they do not present any problems of compatibility with the material usually used for manufacture.

Finally, different procedures have been established for the application of these adhesives that have served as a base for the small scale preparation of prototypes, which will have to be industrially validated and adapted to different production processes.

The most important industrial benefits that can be derived from using this technology, are summarized in the following points: increase in company competitivity (process times are reduced, product quality is improved and productivity increased); favourable environmental impact; improved safety in storing the adhesives; improvement in working conditions; possibility of diversification for companies favouring job creation.